Well bit



Aug. 4, 1936. A. w. KAMMERER WELL BIT Filed July 12, 1935 2 She ets-Sheet 1 w Al n i Jim/07hr Arc/Mr h. Maw/rarer MM Aug. 4, 1936.

A. W. KAMMER ER WELL BIT Filed July 12, 1955 2 Sheets-Sheet 2 w a w 1 M3. flwwww v w j n Patented Aug. 4, 1936 UNITED STATES PATENT OFFICE WELL BIT Archer W. Kammerer, Fullerton, Calif. Application July 12, 1935. Serial No. 31,012 Claims. (Cl. 255-71) This invention relates to a well drilling tool, and relates more particularly to a well bit for use in connection with the rotary method of well drilling. It is a general object of the invention to provide a practical and effective well drilling bit combining the operative features of the drag type bit and the rock or roller type bit.

There are two general or main classes of bits employed in the rotary method of well drilling, l0 viz., the drag type bit, and the rock or roller type bit. The drag type of well bit involves cutting blades or teeth fixed on the body or shank of the tool and operable to remove the formation through a scraping or shearing action. The drag type of well bit is particularly adapted for use in comparatively soft earth formations. The rock or roller type of bit includes one or more roller cutters rotatably mounted on the shank and provided with cutting parts at their periphcries for crushing the formation. In certain districts, shale or other earth formations are encountered in which the drag type of drilling bit is of little utility, as its cutting blades slide or skid over the formation upon being dulled so as to have very little cutting action. The roller type of drill is not effective in certain types of formations, as the cutting parts soon become filled or covered with the cuttings so that the rollers merely roll or track over the formation 3 without crushing or cutting it. g

It is an object of the present invention to provide a well drilling bit including both cutters of the drag type and cutters of the roller or rock type. g 35 It is another object of the invention to provide a well drilling bit of the character mentioned that is particularly effective in shale formations or other formations that are usually very diflicult to drill by means of the usual roller or drag types 40 of drills. In accordance with the present invention, roller type cutters are mounted ahead of blades or drag type of cutters, so as to roughen or make the formation irregular so that the drag blades or cutters are effective in removing it.

45 It is another object of the invention to provide a well drilling tool of the character mentioned that is simple, practical, and inexpensive of manufacture.

Another object of the invention is to provide a 50 well drilling bit of the character mentioned that includes mounting means for the cutters whereby each of the cutters or sets of cutters is mounted so as to be independently detachable from the shank. 65 other objects and features of the invention will be best and more fully understood from the following detailed description of typical forms and applications of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of one form of the bit 5 provided by my present invention, showing it mounted on the lower end of an operating string and in operation within a well bore. Fig. 2 is a enlarged vertical detailed sectional view of the bit, being a view taken through the mountings of 10 the roller cutters. Fig. 3 is an enlarged bottom elevation of the bit. Fig. 4 is an enlarged transverse detailed sectional view taken as indicated by line 4--4 on Fig. 2. Fig. 5 is a vertical detailed sectional view of the bit, being a view taken substantially as indicated by line 5-5 on Fig. 4. Fig. 6 is an enlarged vertical detailed sectional view taken substantially as indicated by line 6--5 on Fig. 5, showing a blade cutter and its mounting pin in elevation. Fig. 7 is an enlarged detailed sectional view taken as indicated by line on Fig. 2. Fig. 8 is a vertical detailed sectional view through the roller cutter mountings of another form of the invention, and Fig. 9 is a fragmentary detailed sectional view through the cutting blades of the bit shown in Fig. 8.

The bit provided by the present invention and illustratedin Figs. 1 to '7 includes, generally, a body or shank l0, rock or roller cutters II detachably mounted on the shank Ill, and blade or drag type cutters l2 detachably mounted on the shank.

The body or shank I0 is adapted to be mounted and operated on the lower end of an operating string P of drill pipe. In Fig. 1 of the drawing I have illustrated the shank l0 attached to the lower end of a typical drill collar C on the lower end of the operating string P. The body or shank ll) of the bit may be a simple integral member and may be cylindrical in its general configuration. A tapered pin [3 may be provided on the upper end of the shank Ill to thread into a. socket M in the lower end of the drill collar C. The lower end part l5 of the shank is preferably of greater diameter than the upper end portion of the shank. A main or central fluid passage I6 is provided in the upper end of the shank ID to communicate with the'fluid passage of the drill collar C.

The roller cutters II are mounted at the lower end of the shank ill to act on the formation at the bottom of the well bore B. In accordance with the broader aspects of the invention, there may be any desired number of roller cutters provided on the bit and they may be mounted and related in various manners. In the simple preferred embodiment of the invention illustrated in the drawings, there are two like pairs or sets of roller cutters mounted below the lower end of the shank Ill. Each pair or set of roller cutters II is detachably mounted on the shank In.

The mounting means for each pair of rock cutters includes a flange H to engage against the lower end |8 of the shank, a pin l8 projecting from the flange, and spaced downwardly projecting legs 20 for carrying the cutters. The two flanges |1 seat directly against or directly about the lower end I I of the shank. The two mounting flanges l1 are preferably alike in size and shape and are segmental in their plan configuration, having their outer edges flush with the periphery of the lower portion l5 of the shank. The chordal or inner sides 22 are straight and spaced apart at opposite sides of the central longitudinal axis of the shank.

The mounting pins I! may be integral with the flanges l1 and may be of round cross sectional configuration. There may be a single centrally located pin l9 projecting upwardly from each flange |1 into an opening or socket 23 in the shank In. The upper end portions of the pins l9 are tapered or frusto-conical and the upper portions of the socket 23 are shaped to effectively receive or carry the pins. In accordance with the invention, means is provided for holding the pins l9 against movement in the sockets 23. A rod or bolt 24 is arranged through a diametric opening 25 in the main portion l5 of the shank. An enlarged part or head 26 is provided on one end of the bolt 24. The head 26 is tapered or provided with outwardly divergent sides, and the end portion of the opening 25 is shaped to conform to the configuration of the head. The enlarged end portion of the opening 25 intersects an edge part of one of the sockets 23, and a notch 21 is provided in the pin l9 to register with the intersecting portion of the opening 25. The head 26 cooperates with or fits into the notch 21 to positively hold the pin i9 against movement in the socket 23. A tapered or frusto-conical sleeve 28 is slidably mounted on the plain and of the bolt 24. The end part of the opening 25 isshaped to receive the sleeve 28 and intersects the notch 21 of the other mounting pin IS. The sleeve 28 flts into the notch 21 to hold the pin against movement. A nut 29 is screwed-threaded on the rod 24 to clamp the head 26 and the sleeve 28 in position. In the preferred construction, the. end of the head 26 and nut 29 are inset orcountersunk within the opposite ends of the opening 25.

The legs 23 project downwardly from the flanges 21 to mount or carry the roller cutters II. In the embodiment of the invention being described, there are two spaced parallel legs 20 projecting downwardly from each flange H. In the particular case illustrated, the legs 20 project downwardly and outwardly from the flange. Each pair of roller cutters consists of an inner cutter 30 rotatably mounted between a pair of legs 23 and an outer cutter 3| at the outer side of the outermost leg 20. A single pin 32 may be carried by each pair of legs 28 to carry a pair of roller cutters The pins 32 extend through transverse openings 33 in the legs 20. A head 34 is provided on the outer end of each pin 33 to fit a socket 35 in the outer end of a cutter 3|. The inner ends of the pins 32 may be welded in the openings 33 of the innermost legs 20. The

cutter-carrying pins 32 are inclined upwardly and outwardly relative to the axis of rotation of the bit so that the cutters 3| and 32 are rotatable about axes inclined relative to the axis of rotation of the tool. The axes of rotation of the two pairs of roller cutters may be in a vertical plane diametric of the vertical or longitudinal axis of the shank I I.

The inner cutter 38 of each pair of roller cutters is cylindrical and is provided at its periphery with cutting parts or teeth 36 for acting on the formation at the bottom of the well bore. The outer cutters 3| have inner cylindrical parts provided with cutting parts or teeth 31 for acting on the formation at the bottom of the well bore. The cutters 3| may be of larger diameter than the innercutters 30 so as to have their cutting parts 31 in the same horizontal plane as the cutting parts 36. The outer roller cutters 3| are provided with tapered outer ends provided with cutting parts 33 for engaging or forming the side walls of the well bore B. The conical or tapered outer ends 38 of the outer cutters, in engaging the side walls of the well bore, operate to effectively guide the bit and prevent eccentric or undesirable movement of the drill. In the drawings, the cutting parts 36 and 38 are cylindrical and concentric with the axes of the cutters 30 and 3|, it being understood that they may be pitched or inclined as desired.

The drag type or blade cutters |2 are mounted behind or at the rear of the roller cutters II to engage and act on the formation after it has been acted upon by the roller cutters. In the embodiment of the invention illustrated in the drawings, where there are two sets or pairs of roller cutters II, the bit may be provided with only two drag type cutters or blades l2, one spaced at the rear of each pair of roller cutters II. The cutters |2 may be in the nature of simple integral blades having their upper ends arranged between the spaced chordal edges 22 of the flanges l1 and in engagement with the lower end l8 of the shank. The two blade cutters l2 project downwardly from between the flanges l1 to engage the formation at the bottom of the well bore. The blades or cutters l2 may be bowed or bent to have their lower projecting parts ofl'set rearwardly of their upper ends, as illustrated in Fig. 6 of the drawings.

The lower or active ends of the blades l2 are provided with suitable cutting edges. In the particular case illustrated in the drawings, each blade I2 is provided with a main outer cutting edge 40 and stepped inner cutting edges 4| and 42. The inner portions of the blades I2 are stepped upwardly and inwardly to provide the cutting edges 4| and 42 for destroying the core or formation at the center of the bore. The cutting blades I2 may project outwardly beyond the lower end portion I5 of the shank to have vertical cutting edges 43 at their outer ends. The cutting edges 43 are adapted to engage the formation at the side walls of the well bore B. The cutting blades l2 are spaced at suitable distances rearwardly of the roller cutters relative to the direction of rotation of the bit so that their cutting edges 40, 4| and 42 engage the formation at the bottom of the well bore after it has been acted upon by the roller cutters 30 and 3|. It is to be noted that, in the particuiar construction illustrated in the drawings, the cutting edges of the blades |2 do not fall in or make cuts of the same configuration as the roller cutters 30 and 3|. It is to be understood that the cutting edges 01' the blades l2 may be shaped to follow in and act upon-the cuts made by the roller cutters and 3| if desired. The means for detachably mounting th blades l2 on the lower end of the shank It may be similar to the means for mounting the flanges H, i. e., it may include a pin 45 projecting upwardly from each blade and held in a socket 46 in the shank by a transverse bolt 41. The two blades l2 may be independently attached to the shank l0; however, their abutting inner edges 48 may be welded together if desired. When the edges 48 of the two blades I! are welded together, the two cutting blades form an assembly that may be detached from the shank as a unit. The retaining bolt 21 is provided at its one end with a tapered enlargement or head 48 which fits a notch in a pin 45 to hold it in the socket 46. A tapered sleeve 50 is provided on the other end of the bolt 41 to cooperate with a notch 5| in a pin 45 to hold the pin against displacement. A nut 52 is screw-threaded on the outer end of the bolt 41 to clamp the head 49 and the sleeve 50 in their retaining positions.

The invention provides means for passing circulation fluid through the bit to discharge into the bottom of the well bore. Branch openings or fluid passages 60 extend downwardly and outwardly from the lower end of the passage I6 to the lower end I8 01' the shank. Openings GI are provided in the flanges H to register with the lower ends of the openings 60 and to discharge the circulation fluid downwardly into the well bore. In the particular construction illustrated in the drawings, the openings 6| occur at points spaced forwardly of the roller cutters II, it being understood that they may be positioned at other points relative to the cutting parts of the bit if desired.

It is believed that the operation of the drilling bit illustrated in Figs. 1 to 7, inclusive, will be readily apparent from the foregoing detailed description. During operation, the bit is rotated in a forward or clockwise direction so that the roller cutters 30 and 3| act on the formation at the bottom of the well bore ahead of the drag blades l2. The cutting parts or teeth 36, 31, and 38 of the roller cutters operate to crush and roughen the formation so that it is readily cut and removed by the cutting edges of the blades l2. As the formation is first roughened by the roller cutters 30 and 3| and is then cut or removed by the blade cutters l2, the roller cutters are not subject to becoming mudded up, and the cutting blades l2 act to cut the formation rather than skid or slide on the formation. In practice, the bit is very efiective and rapid in its operation, as it has the desirable operative characteristics of both the roller type bit and the drag type bit. The cutters II and I2 are mounted on the shank so as to be easily and quickly removed and replaced. It is to be noted that the cutters may be replaced by cutters of various sizes and cutter units in which the cutting parts are related in various manners. construed as restricted to the specific number and arrangement of cutting parts illustrated in the drawings.

Figs. 8 and 9 illustrate a form of the invention in which the roller cutter mountings and the drag type blades are integral with the shank or body. The bit shown in Figs. 8 and 9 includes a body I0 which is a simple, integral member of substantially the same general configuration as Accordingly, the invention is not to be p the body It. A tapered threaded pin I3 is provided on the upper end of the body II- to i'acllitate the connection 0! the body with a drill collar or the like. The lower end portion I! of the body is enlarged and a main central fluid passage I8 enters the body from the upper end 0! its pin l3". Two sets or pairs of roller cutters I lare mounted on the lower end of the body l0. Two pairs of spaced parallel legs 20' project from the lower end of the body It to carry the roller cutters l I. In accordance with the form oi. the invention being described the legs 20 are integral with the body It). The legs 20 project downwardly and outwardly and the two pairs of legs are disposed at diametrically opposite points on the lower end of the body. The inner cutters 30 of each pair of cutters H is disposed between two adjacent legs 20 and the outer cutter 3| of each pair is positioned at the outer side of the outermost leg 20*. Pins 32 extend through openings in the legs 20* to support the cutters 30 and 3! for rotation. The pins 32"- may be welded or otherwise secured to the legs 20. The cutters 30" and .SI are rotatable about axes inclined downwardly and inwardly relative to the vertical axis of the bit. The roller cutters 30 and 3| are of the same shape as the cutters 30 and 3| and operate in the same manner.

The drag type cutters or the blade cutters I2 project downwardly from the lower end of the body l0 at points spaced at the rear of the pairs of roller cutters I I. In the form of the invention being described the blades I!" are integral with the body Ill. The blades l2 are of the same shape and have the same operation as the blades [2 of the previously described form or the invention. Each blade l2 has an outer cutting edge 40* and an upwardly stepped inner cutting edge 4| at its lower end. An inner cutting part or edge 42 may occur between the blades l2. Each blade l2 has an outer cutting edge or reaming edge 43. Ports 60 extend downwardly from the passage Hi to discharge at the lower end of the body. The operation of the bit illustrated in Figs. 8 and 9 of the drawings is the same as the previously described form of bit. The mountings for the roller cutters H and the blades l2 being integral with the body Ill make the bit simple and inexpensive of manufacture.

Having described only typical preferred forms of my invention, I do not wish to limit myself to the specific details set forth, but wish to reserve to myself any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A well bit including, a body, roller cutters, means for mounting the roller cutters including, flanges engaging the lower end of the body, the inner edges of the flanges being spaced apart, legs projecting downwardly from the flanges, and cutter carrying pins on the legs, and a blade cutter attached to the body and projecting downwardly between the inner edges of the flanges.

6 2. A well bit including. a body, roller cutters,

means for mounting the roller cutters including, flanges engaging the lower end 01 the body, the inner edges of the flanges being spaced apart, legs projecting downwardly from the flanges, and cutter carrying pins on the legs, a blade cutter projecting downwardly between the inner edges of the flanges, and means for detachably securing the blade cutter'to the body.

3. A well bit including, a body, roller cutters,

meansior mounting the roller cutters including, flanges engaging the lower end of the body, the inner edges of the flanges being spaced apart, legs projecting downwardly from the flanges, pins on the legs rotatably carrying the cutters, a pin projecting from each flange and fitting a socket in the body, a bolt in an opening in the body intersecting the two sockets, a tapered head on the bolt cooperating with a notch in one o! the pins, and a sleeve on the bolt cooperating with a notch in the other pin.

4. A well bit including, a body, rollers cutters, means for mounting the roller cutters including, flanges engaging the lower end of the body, the inner edges of the flanges being spaced apart, legs projecting downwardly from the flanges, and cutter carrying pins on the legs, a blade cutter projecting downwardly between the inner edges of the flanges, and means for detachably securing the blade cutter to the body including, a pin on the blade fltting a socket in the body, a bolt in an opening in the body, and a part on the bolt cooperating with a notch in the said pin.

5. A well tool including a body, roller cutters,

, means for mounting the roller cutters including flanges held against the lower end of the body, the inner edges of the flanges being spaced apart, and legs projecting from the flanges and carrying the roller cutters, blade cutters projecting downwardly between the inner edges of the flanges, and means independently detachably securing the blades to the body.

6. A well tool including a body, roller cutters, means for mounting the roller cutters including flanges held against the lower end of the body, the inner edges of the flanges being spaced apart, and legs projecting from the flanges and carrying the roller cutters, blade cutters projecting downwardly between the inner edges of the flanges, and means independently detachably securing the blades to the body including a pin on each blade fitting a socket in the body, and a removable member engaging the pins in the sockets to hold the pins against downward movement.

7. A well tool including a body, roller cutters, means for mounting the roller cutters including flanges held against the lower end or the body, the inner edges or the flanges being paced apart, and legs projecting from the flanges and carrying the roller cutters, blade cutters projecting downwardly between the inner edges of the flanges, the upper ends of the blades bearing directly against the lower end of the body. pins projecting from the upper ends of the blades and extending into sockets in the body, and removable means holding the pins against displacement from the sockets.

8. A well tool including a body. two roller cutter carrying units detachably mounted on the lower end of the body, each unit including a flange seating directly on the lower end of the body, the inner edges of the flanges being spaced apart, a blade cutter projecting downwardly between the inner edges of said flanges, the upper ends of the blade cutter seating against the lower end of the body, and a pin projecting from the blade cutter and removably held in a socket in the body.

9. A well drilling bit including a body, pairs oi roller cutters, means for carrying the roller cutters including pairs of spaced legs projecting from and integral with the lower end of the body, and a pin carried by each pair of legs rotatably supporting a pair of roller cutters, and blade cutters projecting from the lower end of the body and spaced at the rear of the legs, the blade cutters being integral with the body.

10. A well bit including, a body, spaced pairs of legs projecting from the lower end of the body,

a pin carried by each pair of legs, roller cutters supported by each pin for rotation about downwardly and inwardly inclined axes, and cutting blades rigid with the body and projecting from its lower end in spaced relation to the pairs of legs. 1

- ARCHER W. KAMMERER. 

